1. Field of the Invention
The present invention relates generally to orthotic devices, and more particularly to electrostimulation and bracing to treat arthritic joints. Some embodiments relate to knee braces and electrodes adapted to provide electrostimulation and to conform to a wearer's anatomy.
2. Description of the Related Art
Orthotic devices generally include a substantially rigid biomechanical element that forms the basis of the skeletal support that is required for the majority of these devices, which include braces, supports and splints.
The human knee generally comprises an articulated joint between the thigh and the calf muscles that supports the weight of the human body while the person is standing, walking or running. The knee joint is primarily held together by four ligaments; namely, the anterior and posterior cruciate ligaments and the medial and lateral collateral ligaments. The knee joint can be weakened or damaged by injuries resulting in cartilage damage and ligament strain, which may be the result of trauma, repetitive sporting activities or overly aggressive exercising, or physiological problems such as osteoarthritis. In particular, the human knee may be subjected to a variety of damaging stresses and strains particularly during running and jumping movements. Athletes, in particular, are apt to incur a knee injury as a result of a blow to the knee or to a twisting of the knee, which can commonly occur in various contact sports or high stress sports, such as football or skiing.
There are a variety of knee braces available on the market or through healthcare providers. These range from braces that attempt to totally immobilize the knee, to functional braces that may be as simple as flexible elastic bandages that are intended to provide some flexibility while eliminating lateral movement of the ligaments that support the knee. Some of these products are intended to be worn as a relatively permanent device for long-term wear while others are intended to be worn for a short period of time to support a weakened knee during strenuous activities. These functional braces have as their primary object to allow for pivoting the knee while preventing any unnatural movement that may aggravate the knee ligaments. Some braces are meant to provide a constant or variable “unloading” force on the knee joint to alleviate pain, such as pain caused by osteoarthritis. While functional braces are intended to allow for a natural movement of the knee joint while a person undergoes walking, running, jumping, skating, various other athletic activities, they are also intended to prevent sudden movement of the upper and lower legs to one side or the other and to prevent twisting or rotation of the lower leg relative to the upper leg about the vertical axis, and/or to provide a pain-relieving force to the joint.
Typically, the knee braces are held in place by flexible straps, which wrap about the user's thigh and calf above and below the knee, respectively. In this manner, the rigid hinge or hinges of the knee brace remain positioned relative to the user's knee so as to mimic the hinged joint of the knee. However, it is not uncommon for the user's bodily motions to cause the flexible straps to move relative to the person's leg, thereby misaligning the knee brace with respect to the knee. This movement of the brace straps with respect to the user not only causes misalignment and therefore misapplication of the orthotic device, but also causes irritation of the user's skin by this unintended rubbing.
Orthotic devices must engage effectively with soft tissue in order to provide the desired support. In many parts of the body the soft tissue will move, for example by expanding or contracting as result of muscle movement. As soft tissue changes shape, parts of the skin may lose contact with the liner of the orthotic device. This reduced contact with the liner can cause the orthotic device to change position, or move relative to the user and therefore become ineffective. Typical devices provide measures for tightening the brace to maintain contact. This causes discomfort, prevents the skin from breathing, and can irritate the skin about the edges of the device and the liner.
The objective of any rigid knee brace is to exert a predictable force on the user's underlying skeleton. In particular, the objective is to exert a force on the tibia with respect to the femur in the user's body mass above the knee. By definition, knee braces are applied to soft tissue lying between the brace and the user's skeleton. Any rigid element may include some form of liner that contacts the body of the user. The liner may have an outer fabric that is designed to contact the user's skin directly or, alternatively, to engage with clothing that a user may be wearing about the part of the anatomy to which the orthotic device is to be attached. Soft tissue is mobile and moves in a cycle corresponding to a user's gait, whether it be through running, walking or other physical movement common to the human knee. The most mobile soft tissue is the quadriceps mechanism lying in front of the femur in the anterior thigh region. The central reference point for a knee brace is the knee joint line. In construction, an orthotic device such as a knee brace would use a joint mechanism, which mimics the movement of the joint to be supported, such as the knee, which is not just a simple hinge. Since each user's body shape is unique, the interface between the orthotic device and the user's leg cannot be predetermined in the manufacture of such a device.
Degenerative joint disease, osteoarthritis, and other joint diseases or injuries may be treated through various methods of electrical stimulation. Methods of electrostimulation include Neuromuscular Electrical Stimulation, Interferential Stimulation, High Volt Galvanic Stimulation, Electromagnetic and Pulsed Electromagnetic Field Stimulation, Transcutaneous Electrical Nerve Stimulation, Transcutaneous Electrical Stimulation for Arthritis (TESA), and Micro Current Electrical Stimulation.
Osteoarthritis continues to be a growing issue in today's active, aging population. As people live longer and more dynamic lives, the need for solutions to joint deterioration becomes apparent. One specific factor is the progressive degeneration of the articular cartilage of the joint. Traditional means of treatment include NSAIDS, which only treat the pain and inflammation associated with the disease, and have negative side-effects in the gastrointestinal tract, liver, and kidneys. (Zizic T M, The treatment of osteoarthritis of the knee with pulsed electrical stimulation. J Rheumatol. 1995; 22:1757-1761.) Other treatments include total knee arthroplasty (TKA), which partially or completely replaces the knee joint. This method addresses both the pain and underlying physical degeneration by simply removing and replacing portions of the joint, but it is quite invasive. TKA also has long, painful recovery times, is extremely expensive, and has the potential for complicated and risky revision surgeries in patients under a certain age.
The use of electrical stimulation has been studied in a number of clinical and scholarly papers, and has been shown to reduce pain, increase range of motion (ROM), and most importantly, delay the need for TKA. (Electrical Stimulation helps delay knee replacement surgery. Mont M A, Hungerford D S, Caldwell J R, Hoffman K C, Zizic T M. BioMechanics Volume CII, Number 5, May 2005)
Similarly, the use of support and unloading braces/orthoses to treat osteoarthritis has been well documented and accepted in the medical field. Braces/orthoses can include, but are not limited to designs with a fully rigid construction, such as a hard frame; semi-rigid construction such as a soft wrap/sleeve/strap with rigid inserts; or non-rigid construction such as a wrap/sleeve/strap without rigid inserts.
Other treatments include taping methods designed to promote range of motion and support of muscles and joints, sometimes without wrapping completely around said anatomy. Instead, an elastic tape is stretched over the joint or structure, creating support for soft tissue surrounding the affected area. This technique is commonly known as “Kinesio Taping”, drawing its name from the science of kinesiology. The tape can be a laminated assembly of an elastic backing coupled with an adhesive for the skin. The physical form can be on a roll, sheet, or pre-cut into shapes specific to an area of the anatomy. Integrating an electrode within the tape itself accomplishes a synergistic effect. The tape serves to promote the joint's mechanical healing and range of motion, while the built-in electrode signal treats the degenerative or pain management aspects of the joint or structure. This new integration is both functional and convenient to the user.